JP2005332599A - Plasma display panel and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma display panel preventing generation of electrode defects and dielectric film defects, with high reliability and high dielectric strength. <P>SOLUTION: A front face plate 1 with a plurality of display electrodes 6 formed so as to form surface discharge gaps in between and with a dielectric layer 8 formed so as to cover the display electrodes 6, and a rear face plate 2 with a plurality of address electrodes 11 arranged in opposition to the front face plate 1 so as to form a discharge space in between and so as to constitute discharge cells together with the display electrodes 6 are provided. At least one kind of frit glass with a higher softening point than a glass material used for the dielectric layer 8 coating the display electrodes 6 is used for the display electrodes 6. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a plasma display panel used for a display device or the like and a manufacturing method thereof.

  As a display device for displaying high-definition television images on a large screen, there is an increasing expectation for a device using a plasma display panel (hereinafter referred to as PDP).

  A PDP basically includes a front plate and a back plate. A typical front panel of a PDP is a glass substrate, a display electrode group consisting of a striped transparent electrode and a bus electrode formed on one main surface thereof, and covers the display electrode group to function as a capacitor. And a protective layer made of MgO formed on the dielectric layer. As a glass substrate, a glass substrate by a float method suitable for the production of a glass that is easy to increase in area and has excellent flatness is formed, a transparent electrode is formed by a thin film process, and an Ag material is used to ensure conductivity on the transparent electrode. A bus electrode is formed by forming a paste containing a predetermined pattern and then firing. Furthermore, in order to improve contrast, a light shielding layer is formed between display electrodes, a dielectric layer is formed by applying and baking a dielectric paste so as to cover the whole, and finally a protective layer made of MgO is widened. It is formed using a known thin film forming technique.

  On the other hand, the back plate is composed of a glass substrate, a stripe-shaped address electrode formed on one main surface of the glass substrate, a dielectric layer covering the address electrode, a partition formed thereon, and between each partition. The formed phosphor layers emit red, green and blue light respectively.

  The front plate and the back plate are hermetically sealed with their electrode forming surfaces facing each other, and a discharge gas such as Ne—Xe is sealed at a pressure of 400 Torr to 600 Torr in the discharge space formed by the barrier ribs.

  This PDP discharges by selectively applying a video signal voltage to the display electrodes, and the ultraviolet rays generated thereby excite each color phosphor layer to emit red, green, and blue light, and display a color image. Realized.

In the PDP having such a configuration, the display electrode is composed of a transparent layer and a bus electrode as a black layer (black electrode) for suppressing external light reflection and a low-resistance conductive layer (metal electrode) mainly composed of metal. However, as disclosed in Patent Document 1, for example, the display electrode group is composed of a plurality of layers formed on the front side substrate, and one of the plurality of layers has a sheet resistance higher than that of the other layers. It has been proposed that the material utilization rate is improved and the man-hours are reduced by forming the light shielding portion with the black layer of the display electrode group.
JP 2002-83547 A

  However, conventional materials and process conditions have problems such as electrode defects such as blisters in the electrode layer and film defects such as bubbles in the dielectric layer, resulting in dielectric breakdown and reduced yield.

  SUMMARY OF THE INVENTION The present invention solves the above-described problems, and an object of the present invention is to provide a PDP having high reliability and high withstand voltage, which prevents the occurrence of electrode defects and dielectric film defects.

  According to a first aspect of the present invention, there is provided a front plate in which a plurality of display electrodes are arranged so as to form a surface discharge gap therebetween, and a dielectric layer is formed so as to cover the display electrodes. And a back plate formed by arranging a plurality of address electrodes so as to form a discharge cell with the display electrode while facing the front plate so that a discharge space is formed between the front plate and the display plate. The electrode is characterized in that at least one kind of frit glass having a softening point higher than that of the glass material used for the dielectric layer covering the display electrode is used.

  In the invention according to claim 2 of the present invention, the display electrode is composed of an electrode layer including at least a black layer and a conductive layer, and the frit glass included in the conductive layer is contained closest to the display surface side. The softening point of the frit glass is higher than the softening point of the glass material used for the dielectric.

  In the present invention, the bus electrode is made of a conductive material containing Ag.

  Further, the plasma display manufacturing method of the present invention is formed by firing the dielectric layer at a temperature lower than the softening point of the frit glass included in the display electrode and higher than the softening point of the glass material included in the dielectric. It is characterized by doing.

  According to the present invention, the electrode photosensitive paste frit glass having a higher softening point than the dielectric paste frit glass, and the dielectric layer of the frit glass contained in the electrode photosensitive paste is used. By forming by firing at a temperature lower than the softening point, defects in the electrode layer and the dielectric layer can be prevented, and a high-quality PDP can be stably provided with a high yield.

  Hereinafter, a PDP according to an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a cross-sectional perspective view showing a main part of a main configuration of a PDP according to an embodiment of the present invention. In the figure, the z direction corresponds to the thickness direction of the PDP, and the xy plane corresponds to a plane parallel to the PDP surface. As shown in FIG. 1, the PDP includes a front plate 1 and a back plate 2 that are arranged to face each other so that a discharge space is formed. FIG. 2 is a cross-sectional view of the front plate taken along line AA in FIG.

  In the front plate 1 of FIG. 1, a plurality of striped transparent electrodes 4 are formed in parallel on the surface of the front glass substrate 3 on the back plate 2 side with the x direction as the longitudinal direction. Further, as shown in FIG. 2, the electrode layer 5 having a narrower width and superior conductivity than the transparent electrode 4 is disposed along the edge of the transparent electrode 4 to form a bus electrode, thereby forming the display electrode 6. Has been. The plurality of display electrodes 6 are formed so as to form a surface discharge gap therebetween, and are formed between the electrodes on the side where the surface discharge gap is not formed, that is, the transparent electrode on the edge side where the bus electrode 5 is formed. Between 4, a light shielding layer 7 is provided for shielding white color from the phosphor layer when no light is emitted and improving contrast.

  Here, the transparent electrode of the display electrode group is not limited to the stripe shape. Furthermore, even in a display electrode group without a transparent electrode, an aperture ratio in which a surface discharge gap is formed between the display electrodes and light emission of the phosphor can be sufficiently extracted Should be obtained.

Hereinafter, the front plate 1 in the present embodiment will be described in detail with reference to FIG. First, a transparent electrode material such as ITO or tin oxide (SnO ² ) is uniformly formed on the front glass substrate 3 formed by the float method by a sputtering method or the like, and then desired by using a photolithography method. The transparent electrode 4 is obtained by patterning into a shape.

  The electrode layer 5 that is disposed along the edge of the transparent electrode 4 and serves as a bus electrode includes at least a black layer 5a and a conductive layer 5b made of a conductive material containing Ag. That is, in one embodiment of the PDP shown in FIG. 2, the display electrode 6 of the front plate 1 is composed of the transparent electrode 4 and the electrode layer 5 composed of at least the black layer 5a and the conductive layer 5b.

Next, the black layer 5a and the light shielding layer 7 are formed. As the material of the black layer 5a, at least a black pigment such as a metal oxide, a conductive material, frit glass (PbO—B ₂ O ₃ —SiO ₂ type, Bi ₂ O ₃ —B ₂ O ₃ —SiO ₂ type, etc.), A photosensitive paste containing an organic solvent or the like as a component is used. The material of the light shielding layer 7 includes at least a black pigment such as a metal oxide, frit glass (PbO—B ₂ O ₃ —SiO ₂ or Bi ₂ O ₃ —B ₂ O ₃ —SiO ₂ or the like), an organic solvent, or the like. Is used as a component. Note that the black layer 5a and the light shielding layer 7 may have a blackish color such as gray instead of a true black color.

  The black layer 5a and the light shielding layer 7 are formed by forming a film using the paste by a screen printing method, a sheet method, or the like, and then exposed by irradiating ultraviolet rays through an exposure dry plate having a desired pattern, and then an alkaline developer. A predetermined pattern is formed by developing using. Here, it is preferable that the black layer 5a and the light shielding layer 7 are simultaneously formed of the same material. This increases the material utilization efficiency and reduces the number of formation steps.

Next, a conductive layer 5b made of a conductive material containing Ag is formed on the black layer 5a. As the material of the conductive layer 5b, a conductive material containing Ag, frit glass (PbO—B ₂ O ₃ —SiO ₂ type, Bi ₂ O ₃ —B ₂ O ₃ —SiO ₂ type, etc.), an organic solvent, etc. A photosensitive paste contained as a component is used. As the formation method, similarly to the formation method of the black layer 5a and the light-shielding layer 7, a film is formed using the paste by a screen printing method, a sheet method, etc., and then ultraviolet rays are passed through an exposure dry plate having a desired pattern. The conductive layer 5b having a predetermined pattern can be formed by exposing the substrate to light and then developing with an alkaline developer.

  Then, after drying the black layer 5a and the conductive layer 5b, which are the electrode layers 5 having a predetermined pattern shape, and the light shielding layer 7, the highest softening point among the softening points of the frit glass material used for each layer. By baking at the above temperature, the electrode layer 5 and the light shielding layer 7 can be formed.

In the present invention, the photosensitive paste for a plurality of electrode layers such as the black layer 5a and the conductive layer 5b constituting the electrode layer has a softening point higher than the softening point of the glass material used for the dielectric layer to be formed later. At least one kind of frit glass having dots is used. Later, by firing the dielectric layer at a temperature lower than the softening point of the frit glass of the electrode layer, it is possible to prevent the frit glass of the electrode layer from being resoftened during the firing of the dielectric, and to generate dielectric film defects. Can be avoided. Examples of the frit glass having a softening point higher than that of the glass material used for the dielectric layer include the PbO—B ₂ O ₃ —SiO ₂ system and Bi ₂ O ₃ —B ₂ O ₃ —SiO ₂ system described above. The frit glass may be used, and may be appropriately selected and used depending on the glass material for forming the dielectric layer.

  In the present invention, it is more preferable that the electrode layers including frit glass having a lower softening point are laminated in order from the display surface side. For example, a frit glass having a softening point of 570 ° C. is used for the black layer 5a and a conductive layer 5b is a glass material having a softening point of 560 ° C. for the dielectric layer. By adopting such a configuration, when the electrode layer is fired, the frit glass of the upper conductive layer 5b is first softened, and the decomposition material from the lower black layer 5a is less likely to be thermally decomposed. It can be avoided and the occurrence of electrode defects can be prevented. Moreover, the frit glass which has the low softening point in the black layer 5a which is a lower layer fully softens by a baking process, and can fully ensure the adhesiveness to a glass substrate or a transparent electrode layer.

Next, a dielectric layer 8 made of a dielectric glass material is formed so as to cover the display electrodes 6 and the light shielding layer 7. As a forming method, a screen printing method, a die coating method, or the like is used. After coating on the entire surface of the screen display region, the solvent contained in the paste is removed by a drying process using a drying furnace. As the dielectric glass material, a dielectric glass powder (PbO, SiO ₂ , B ₂ O ₃ , Al ₂ O _3, etc.) is used.

  After the dielectric film is dried, the dielectric layer 8 is formed by baking at a temperature not lower than the softening point of the glass material used for the dielectric layer and not higher than the softening point of the frit glass used for the electrode paste. It is possible to prevent the frit glass of the electrode layer from being softened again, and to suppress film defects of the dielectric layer and diffusion of the frit glass of the electrode layer. At this time, the film thickness of the dielectric layer 8 is about 30 to 40 μm.

  Further, a protective film 9 is laminated over the entire area of the dielectric layer 8. The protective film 9 is formed by depositing about 600 nm of MgO on the dielectric layer 8 by the electron beam evaporation method, and thus the front plate 1 is completed.

  In the back plate 2, a plurality of address electrodes 11 are arranged in parallel on the surface of the back glass substrate 10 on the front plate 1 side so as to form discharge cells with the display electrodes 6 in a stripe shape with the y direction as the longitudinal direction. Further, a dielectric layer 12 is formed so as to cover the address electrode 11. On the dielectric layer 12, a stripe-shaped partition wall 13 is disposed so as to be positioned on a region between the address electrodes 11. Phosphor layers 14 that emit light in red, green, and blue are regularly arranged and formed in striped recesses formed by the barrier ribs 13 and the dielectric layers 12.

  As shown in FIG. 1, the front plate 1 and the back plate 2 having such a configuration are arranged so that the address electrodes 11 and the display electrodes 6 face each other so as to be substantially orthogonal to each other. The discharge space 15 surrounded by the stripe-shaped recess formed of the dielectric layer 12 and the protective film 9 of the front plate 1 is filled with a discharge gas, and the outer peripheral edges of the front plate 1 and the back plate 2 are sealed. Sealed with glass. Here, as shown in FIG. 2, a region where a pair of adjacent display electrodes 6 and one address electrode 11 intersect is a discharge cell related to image display. The discharge space 15 is filled with a discharge gas (filled gas) made of a rare gas component such as He, Xe, or Ne at a pressure of about 400 Torr to 600 Torr.

  In this PDP, short-wave ultraviolet rays (wavelength of about 147 nm) are generated by discharge generated in each discharge cell, and the phosphor layer 14 is excited to emit light by the ultraviolet rays, so that an image can be displayed.

  ADVANTAGE OF THE INVENTION According to this invention, the defect of an electrode layer and a dielectric material layer can be prevented, and high quality PDP can be provided stably with a high yield.

The perspective view which shows the main structures of the plasma display panel by one embodiment of this invention Sectional drawing cut | disconnected by the AA line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front plate 2 Back plate 3 Front glass substrate 4 Transparent electrode 5 Electrode layer 6 Display electrode 7 Light-shielding layer 8 Dielectric layer 9 Protective film 10 Rear glass substrate 11 Address electrode 12 Dielectric layer 13 Partition 14 Phosphor layer 15 Discharge space

Claims (4)

A front plate in which a plurality of display electrodes are arranged so that a surface discharge gap is formed and a dielectric layer is formed so as to cover the display electrodes, and a discharge space is formed between the front plates. And a back plate formed by arranging a plurality of address electrodes so as to form a discharge cell with the display electrode, and a dielectric layer covering the display electrode on the display electrode A plasma display panel characterized in that at least one type of frit glass having a softening point higher than that of the glass material used is used. The display electrode is composed of an electrode layer including at least a black layer and a conductive layer. In the frit glass included in the conductive layer, the softening point of the frit glass contained closest to the display surface side is a dielectric. The plasma display panel according to claim 1, wherein the plasma display panel is higher than a softening point of a glass material used for the display. The plasma display panel according to claim 2, wherein the conductive layer is made of a conductive material containing Ag. The method for manufacturing a plasma display according to claim 1, wherein the dielectric layer is fired at a temperature lower than a softening point of the frit glass included in the display electrode and higher than a softening point of the glass material included in the dielectric. A method of manufacturing a plasma display, comprising: forming a plasma display.

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